To lengthen the sink drain there are a couple ways.
Moving bathroom plumbing.
Rerouting bathroom drainage in a home that has a standard wood subfloor set on joists is just a matter of getting the pipe and vent configurations correct.
Moving a shower involves changing pipes in the wall and under the floor.
For 15 inches you can leave the vent as is and lengthen only the sink drain.
For a basic project in zip code 47474 with 1 piping run the cost to move plumbing starts at 678 832 per piping run.
2 free plumbing diagrams are available.
To estimate costs for your project.
Determine the new bathroom configuration to suit your existing home drainage system.
It costs roughly 80 to 200 per line to move the plumbing and most fixtures require at least three lines.
Also the possibility of certain changes will depend on what type of dwelling you are renovating.
The drain perforation in the slab stays right where it is now.
If your foundation is slab on grade.
While it s possible to move almost any large fixture beneath the bathroom floor are supporting joists that you should not cut in order to install new drains.
To move any plumbing fixture more than three feet you will have to shell out anything between 500 to 1000.
Moving the toilet is one of those changes in the bathroom layout that is sometimes necessary.
Vent supply pipes and sink drain pipe.
They are all moveable.
Moving the toilet is not a change to be taken lightly.
Think twice before you make this decision and look for ways to avoid moving every plumbing fixture in the bathroom.
But if needed it can be accomplished with substantial plumbing work and a great deal of peripheral work such as opening up a floor or ceiling rerouting pipes and drain flange and re installing the toilet and other fixtures.
Actual costs will depend on job size conditions and options.
Drainage also has to be moved.
Any change in the bathroom floorplan is not easy.
Design your new configuration so that the new drainpipes run parallel to the joists and between them.
This is in addition to the cost of installing the fixture.
Altering where you place the toilet sink or bathtub will cost you big bucks.
Toilets sinks and showers will always require pipes that wind through the house to connect to vent water and drain lines.